I've had my '08 700 xtx for a few months and just love it.  But, it really has a jerking action when doing slow speeds (a couple miles per hour) as in backing up out of parking area, etc.  The dealer says it may be due to the thottle spring being light and that I should try spacers to coil it up more to increase the tension.  The problem is even worse when backing down a grade.  It kind of like hitting the gas, then the engine breaking cuts in and causes the foot to hit the throttle lightly and creates forward motion, etc., etc.  Just a nuisance, but does anybody have the same problem or is it the nature of the beast.  Once you get moving, no problem.  Any thought from the mechanics out there.  Can it be adjusted out?